Magnetics components such as transformers and inductors are often used in circuits. Transformers are useful in electrically isolating one circuit from another, and are also useful in convening a high voltage to a low voltage, or vice versa. Also, inductors are useful as energy storage elements, and as part of a resonant circuit with a capacitor. Thus, magnetics components are important in many circuits.
One conventional approach to implementing magnetics components in a circuit is to use surface-mountable discrete components. Such discrete magnetics components are generally larger in size than other discrete components because they often have many thick windings for handling large amounts of power and because they often use a ferrite core. Because of their relatively large size, and because they generate a relatively large amount of heat, discrete magnetics components are difficult to use in a compact environment. Also, because discrete magnetics components are surface mounted, there is a relatively high resistance between them when they are coupled together through a substrate such as a printed circuit board.
Another conventional approach to implementing magnetics components in a circuit is to use a magnetics component having planar windings printed in a spiral format on a printed circuit board. Although these magnetics components are used frequently because they are compact, they have been found to have a high leakage inductance and a high parasitic capacitance. As a result, many designers of magnetics components have moved away from implementing magnetics components using planar windings, and toward surface-mountable low-profile magnetics devices such as the one disclosed in U.S. Pat. No. 4,583,068, to Dickens et al. However, such low-profile magnetics devices are not as compact as is desirable.
For the foregoing reasons, there is a need in the an for an implementation of magnetics components which is highly compact and has a low leakage inductance and parasitic capacitance. Such an implementation should allow individual magnetics components to be coupled to one another with a relatively low resistance between them, and the resulting magnetics components should be able to handle relatively large amounts of heat.